* {
    margin: 0;
    padding: 0;
}
/* 顶部 */
body {
    width: 100%;
    min-width: 320px;
    max-width: 640px;
    margin: 0 auto;
    font-size: 14px;
    font-family: -apple-system, Helvetica, sans-serif;
    color: #666;
    line-height: 1.5;
    background-color: #ccc;
}
img {
    vertical-align: top;
}
.app {
    height: 45px;
    margin: 0;
    padding: 0;
}
li {
    list-style: none;
}
.app ul li {
    float: left;
    height: 45px;
    background-color: #333;
    text-align: center;
    line-height: 45px;
    
}
.app ul li:nth-child(1) {
    width: 8%;
}
.app ul li:nth-child(1) img {
    width: 15px;
    vertical-align: middle;
}
.app ul li:nth-child(2) {
    width: 10%;
}
.app ul li:nth-child(2) img {
    width: 35px;
    vertical-align: middle;
}
.app ul li:nth-child(3) {
    position: relative;
    width: 57%; 
    line-height: 1;
}
.content_up {
    color: #fff;
    font-weight: 500;
    position: absolute;
    top: 8px;
    left: 9px;
}
.content_down {
    color: #999;
    position: absolute;
    left: 9px;
    top: 25px;
}
.app ul li:nth-child(4) {
    width: 25%;
    background-color: #F63515;
    color: #fff;
}
/* 搜索 */
.search-wrap {
    position: fixed;
    width: 100%;
    height: 44px;
    overflow: hidden;
    min-width: 320px;
    max-width: 640px;
}
.search-btn {
    position: absolute;
    top: 0;
    left: 0;
    width: 40px;
    height: 44px;
}
.search-btn::before {
    content: "";
    display: block;
    width: 20px;
    height: 18px;
    background: url(../images/sizer.png) no-repeat;
    background-size: 20px 18px;
    margin: 14px 0 0 15px;
}
.search-logoin {
    position: absolute;
    right: 0;
    top: 0;
    width: 40px;
    height: 44px;
    margin: 12px 0 0 15px;
    color: #fff;
}
.search {
    position: relative;
    height: 30px;
    background-color: #fff;
    margin: 0 50px;
    border-radius: 15px;
    margin-top: 7px;
}
.jd-icon {
    width: 20px;
    height: 15px;
    position: absolute;
    top: 7px;
    left: 15px;
    background: url(../images/jd.png) no-repeat;
    background-size: 20px 15px;
}
.jd-icon::after {
    content: "";
    position: absolute;
    top: 0;
    left: 26px;
    display: block;
    width: 2px;
    height: 18px;
    background-color: #ccc;
}
.sou {
    position: absolute;
    top: 8px;
    left: 48px;
    width: 18px;
    height: 15px;
    background: url(../images/jd-sprites.png) no-repeat -81px 0;
    background-size: 200px auto;
}
/* 主体部分 */
.slider img {
    width: 100%;
}
.brand {
    overflow: hidden;
    border-radius: 10px 10px 0 0;
}
.brand div {
    float: left;
    width: 33.33%;
}
.brand div img {
    width: 100%;
}